Question

A stream of electrons and protons are directed towards a narrow slit in a screen (see figure). The intervening region has a uniform electric field $\vec{E}$ (vertically downwards) and a uniform magnetic field $\vec{B}$ (out of the plane of the figure) as

• A. electrons and protons with speed $\frac{\left|\vec{E}\right|}{\left|\vec{B}\right|}$ will pass through the slit
• B. protons with speed $\frac{\left|\vec{E}\right|}{\left|\vec{B}\right|}$ will pass through the slit, electrons of the same speed will not
• C. neither electrons nor protons will go through the slit irrespective of their speed
• D. electrons will always be deflected upwards irrespective of their speed

Answer 1

Answer: (C), (D)

Neither electrons nor protons will go through the slit irrespective of their speed.

And electrons will always be deflected upwards irrespective of their speed.